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Qian Z, Yang H, Li J, Peng T, Huang T, Hu Z. The unique biodegradation pathway of benzo[a]pyrene in moderately halophilic Pontibacillus chungwhensis HN14. CHEMOSPHERE 2024; 354:141705. [PMID: 38494000 DOI: 10.1016/j.chemosphere.2024.141705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/17/2024] [Accepted: 03/11/2024] [Indexed: 03/19/2024]
Abstract
Benzo[a]pyrene (BaP), as the typical representative of polycyclic aromatic hydrocarbons (PAHs), is a serious hazard to human health and natural environments. Though the study of microbial degradation of PAHs has persisted for decades, the degradation pathway of BaP is still unclear. Previously, Pontibacillus chungwhensis HN14 was isolated from high salinity environment exhibiting a high BaP degradation ability. Here, based on the intermediates identified, BaP was found to be transformed to 4,5-epoxide-BaP, BaP-trans-4,5-dihydrodiol, 1,2-dihydroxy-phenanthrene, 2-carboxy-1-naphthol, and 4,5-dimethoxybenzo[a]pyrene by the strain HN14. Furthermore, functional genes involved in degradation of BaP were identified using genome and transcriptome data. Heterogeneous co-expression of monooxygenase CYP102(HN14) and epoxide hydrolase EH(HN14) suggested that CYP102(HN14) could transform BaP to 4,5-epoxide-BaP, which was further transformed to BaP-trans-4,5-dihydrodiol by EH(HN14). Moreover, gene cyp102(HN14) knockout was performed using CRISPR/Cas9 gene-editing system which confirmed that CYP102(HN14) play a key role in the initial conversion of BaP. Finally, a novel BaP degradation pathway was constructed in bacteria, which showed BaP could be converted into chrysene, phenanthrene, naphthalene pathways for the first time. These findings enhanced our understanding of microbial degradation process for BaP and suggested the potential of using P. chungwhensis HN14 for bioremediation in PAH-contaminated environments.
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Affiliation(s)
- Zhihui Qian
- Department of Biology, School of Science, Shantou University, Shantou, Guangdong, 515000, China.
| | - Haichen Yang
- Department of Biology, School of Science, Shantou University, Shantou, Guangdong, 515000, China.
| | - Jin Li
- Department of Biology, School of Science, Shantou University, Shantou, Guangdong, 515000, China; College of Life Sciences, China West Normal University, Nanchong, Sichuan, 637002, China
| | - Tao Peng
- Department of Biology, School of Science, Shantou University, Shantou, Guangdong, 515000, China
| | - Tongwang Huang
- Department of Biology, School of Science, Shantou University, Shantou, Guangdong, 515000, China.
| | - Zhong Hu
- Department of Biology, School of Science, Shantou University, Shantou, Guangdong, 515000, China; Guangdong Research Center of Offshore Environmental Pollution Control Engineering, Shantou University, Shantou, Guangdong, 515063, China.
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Qian Z, Peng T, Huang T, Hu Z. Oxidization of benzo[a]pyrene by CYP102 in a novel PAHs-degrader Pontibacillus sp. HN14 with potential application in high salinity environment. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 321:115922. [PMID: 36027730 DOI: 10.1016/j.jenvman.2022.115922] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 07/25/2022] [Accepted: 07/30/2022] [Indexed: 06/15/2023]
Abstract
Benzo [a]pyrene (BaP) is a type of high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) with potent carcinogenicity; however, there are limited studies on its degradation mechanism. Here, a strain of Pontibacillus sp. HN14 with BaP degradation ability was isolated from mangrove sediments in Dongzhai Port, Hainan Province. Our study showed that biodegradation efficiencies reached 42.15% after Pontibacillus sp. HN14 was cultured with 20 mg L-1 BaP as the sole carbon source for 25 days and still had degradability of BaP at a 25% high salinity level. Moreover, 9,10-dihydrobenzo [a]pyrene-7(8H)-one, an intermediate metabolite, was detected during BaP degradation in the HN14 strain. Genome analysis identified a gene encoding the CYP102(HN14) enzyme. The results showed that the E. coli strain with CYP102(HN14) overexpression could transfer BaP to 9,10-dihydrobenzo [a]pyrene-7(8H)-one with a conversion rate of 43.5%, indicating that CYP102(HN14) played an essential role in BaP degradation in Pontibacillus sp. HN14. Thus, our results provide a novel BaP biodegradation molecule, which could be used in BaP bioremediation in high salinity conditions. This study is the first to show that CYP102(HN14) had the BaP oxidization ability in bacteria. CYP102(HN14) could be essential in removing PAHs in saline-alkali soil and other high salt environments through enzyme immobilization.
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Affiliation(s)
- Zhihui Qian
- Department of Biology, Shantou University, Shantou, Guangdong, 515063, PR China
| | - Tao Peng
- Department of Biology, Shantou University, Shantou, Guangdong, 515063, PR China
| | - Tongwang Huang
- Department of Biology, Shantou University, Shantou, Guangdong, 515063, PR China
| | - Zhong Hu
- Department of Biology, Shantou University, Shantou, Guangdong, 515063, PR China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, Guangdong, PR China.
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Schwarz A, Adetutu EM, Juhasz AL, Aburto-Medina A, Ball AS, Shahsavari E. Microbial Degradation of Phenanthrene in Pristine and Contaminated Sandy Soils. MICROBIAL ECOLOGY 2018; 75:888-902. [PMID: 29080101 DOI: 10.1007/s00248-017-1094-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 10/15/2017] [Indexed: 06/07/2023]
Abstract
Phenanthrene mineralisation studies in both pristine and contaminated sandy soils were undertaken through detailed assessment of the activity and diversity of the microbial community. Stable isotope probing (SIP) was used to assess and identify active 13C-labelled phenanthrene degraders. Baseline profiling indicated that there was little difference in fungal diversity but a significant difference in bacterial diversity dependent on contamination history. Identification of dominant fungal and bacterial species highlighted the presence of organisms capable of degrading various petroleum-based compounds together with other anthropogenic compounds, regardless of contamination history. Community response following a simulated contamination event (14C-phenanthrene) showed that the microbial community in deep pristine and shallow contaminated soils adapted most to the presence of phenanthrene. The similarity in microbial community structure of well-adapted soils demonstrated that a highly adaptable fungal community in these soils enabled a rapid response to the introduction of a contaminant. Ten fungal and 15 bacterial species were identified as active degraders of phenanthrene. The fungal degraders were dominated by the phylum Basidiomycota including the genus Crypotococcus, Cladosporium and Tremellales. Bacterial degraders included the genera Alcanivorax, Marinobacter and Enterococcus. There was little synergy between dominant baseline microbes, predicted degraders and those that were determined to be actually degrading the contaminant. Overall, assessment of baseline microbial community in contaminated soils provides useful information; however, additional laboratory assessment of the microbial community's ability to degrade pollutants allows for better prediction of the bioremediation potential of a soil.
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Affiliation(s)
- Alexandra Schwarz
- Discipline of Biological Sciences, College of Science and Engineering, Flinders University, Adelaide, Australia
| | - Eric M Adetutu
- Medical Biotechnology, School of Medicine, Flinders University, Adelaide, Australia
| | - Albert L Juhasz
- Future Industries Institute, University of South Australia, Adelaide, Australia
| | - Arturo Aburto-Medina
- Centre for Environmental Sustainability and Remediation, School of Sciences, RMIT University, Bundoora, Australia
| | - Andrew S Ball
- Centre for Environmental Sustainability and Remediation, School of Sciences, RMIT University, Bundoora, Australia
| | - Esmaeil Shahsavari
- Centre for Environmental Sustainability and Remediation, School of Sciences, RMIT University, Bundoora, Australia.
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Huang J, Qiao ZX, Tang JW, Wang G. High quality draft genome sequence of the moderately halophilic bacterium Pontibacillus yanchengensis Y32(T) and comparison among Pontibacillus genomes. Stand Genomic Sci 2015; 10:93. [PMID: 26561516 PMCID: PMC4641356 DOI: 10.1186/s40793-015-0085-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 10/19/2015] [Indexed: 11/10/2022] Open
Abstract
Pontibacillus yanchengensis Y32(T) is an aerobic, motile, Gram-positive, endospore-forming, and moderately halophilic bacterium isolated from a salt field. In this study, we describe the features of P. yanchengensis strain Y32(T) together with a comparison with other four Pontibacillus genomes. The 4,281,464 bp high-quality-draft genome of strain Y32(T) is arranged into 153 contigs containing 3,965 protein-coding genes and 77 RNA encoding genes. The genome of strain Y32(T) possesses many genes related to its halophilic character, flagellar assembly and chemotaxis to support its survival in a salt-rich environment.
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Affiliation(s)
- Jing Huang
- State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070 P. R. China
| | - Zi xu Qiao
- State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070 P. R. China
| | - Jing wei Tang
- State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070 P. R. China
| | - Gejiao Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070 P. R. China
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